Brush for dynamo-electric machines



H. R. EDGECOMB.

BRUSH FORDYNAMO ELECTRIC MACHINES.

APPLICATION FILED AUGJO, 19H.

Patented Dec. 2, 1919.

TOR 7 BY fiqmzvmw ATTORNEY S E S S N H w UNITED STATES PATENT OFFICE.

HENRY R. EDGECOIIIB, OE ST. MARYS, PENNSYLVANIA, ASSIGNOR/ TO SPEER CARBON v 7 COMPANY, A. CORPORATION CF PENNSYLVANIA.

BRUSH FOR DYNA1VO-ELECTEIC MACHINES.

To all whom it may concern:

' Be it known that I, HE RY R. EDGE- ooMB, a citizen of the-United States, and a resident of St. Marys, in the county of Elk and Stateof Pennsylvania, have invented a. new and useful Improvement in Brushes for Dyiiamo Electric Machines, of which the followingis a specification.

.My invention relates to current-collecting brushes for electric generators, motors and other dynamo-electric machines, and it has for one of'its objects to provide an improved means for attaching a shunt or pigtail conductor toabrush of the character indicated, whereby the brush and the shunt conductor may beeasily and quickly assembled in a permanent mannerand with good electrical contact between the several parts.

Another object of my invention is to providea simple and rapid'proces's of assemblingbrushes of the above-indicated character.

The single figure of the accompanying drawing is a side view, partially in elevation and partially in section, showing a currentcollecting brush provided with a shunt connection constructed in accordance with my invention.

A large number of shunt attachments have been devised for electric brushes, involving the use of various forms of plugs and screws for holding the shunt conductor firmly in the brush; WVhen screws have been employed for this purpose, it has been necessary to provide countersunk openings in the brushes to receive the heads of the screws, and it has also been necessary, in assembling brushes and shunt conductors by means of screws, to screw the parts together with a screw driver or equivalent tool, which makes the labor cost relatively high.

According to my present invention, I provide an attachment for shunt conductors in which a screw-threaded member is employed, but in which the pitch of the threads upon the screw-threaded member is made sufficiently long to permit the member to be thrust directly into a suitable opening in Specification of Letters Patent.

Application filed August 20, 1917. Serial No. 187,134.

.a screw-threaded pin or plug 3. The

Patented Dec. 2, 1919.

ing, the body portion of the brush 1 is provided with a longitudinal opening to receive a braided shunt conductor 2 and with an intersecting transverse opening to receive pin 3 is provided with one or more threads 4, of long pitch, in order that there may be numerous points of-contact between the screw and the body portion ofthe-brush. The brush may be made of any usual or desired conducting material, such as graphite or a mixture of carbon and metal.

In assembling the brush shown in the drawing, suitable openings are drilled in the body portion of the brush, as indicated, the stranded conductor 2 is thrust into the vertical opening, and the screw 3 is forced firmly into the transverse opening. This constitutes the entire assembling operation, unless the screw employed is too long and projects from its opening, in which case the projecting portion should be clipped off in order that the side of the brush may present a smooth appearance. This, however, will not ordinarily be the case, since the screws are so proportioned, in practice, that the outer end of the screw is forced below the surface of the brush.

This brush construction lends itself well to multiple assembling. Any desired number of brushes may be assembled with their shunt conductors at one operation, by providing a suitabl press having two cooperating platens, placing the brushes upon one of the platens with their transverse openings upward and with their shunt conductors thrust into the longitudinal openings, placing screws of the kind described above in the transverse openings, and finally bringing the other platen down upon the screws to force them into place.

It is of course possible to make use of ordinary multiple threaded fillister head screws in making my improved shunt attachments, in which case the transverse opening in the body portion of the brush should be counterbored, to receive the head of the screw, or provision should be made for removing the head of the screw after the parts are assembled. It isalso entirely practicable to assemble the brush with the axis of the screw coincident with the axis of the shunt conductor at the point of attachment. Many other variations may be made from the exact structure which I have shown and described, and I therefor desire that no limitations be imposed upon my invention except such as are indicated in the appended claims.

I claim as my invention:

1. A current-collecting brush for dynamoelectric machines comprising a body portion of conducting material, a conductor therefor, and means for attaching the said conductor to the said body portion comprising a screw-threaded fastening member adapted to be thrust directly into interlocking contact with the said body portion. v

2. A current-collecting brush for dynamoelectric machines comprising a body portion of conducting material provided with intersecting lon 'tudinal and transverse o nings, a con uctor extendin into one o the said openings, and a screw orced into interlocking contact with the walls of the other opening.

3. A current-collecting brush for dynamoelectric machines comprising a body pore tion of conducting material provided With' intersecting openings, a conductor extending into one of the said openings, and a screw forced into locking contact with the walls of the other opening.

at. The method of assembling current 001 lecting brushes for dynamo-electric ma chines that comprises forming intersecting" body portions, placing a screw in each'gi the remaining openings, and moving the said pressure members-together and forcing the said screws into the said open in s and through the said conductors.

n testimony whereof, I have subscribed my name t n h day Oilfigust 1917. M HENRY R. EDGECOMB. 

